Load sensing technology is a technology for determining a load carried by a certain structure or a machine, or by a component thereof. The structure, machine or component is then provided with one or more load sensors. For example, the machine is an automobile and the individual loads on individual ones of the wheels are determined via the wheel hubs. The information about the loads is used to electronically control, e.g., the amount of power supplied to each driven wheel individually, or the amount of braking applied to each individual wheel, or to adjust the suspension system for each wheel individually, in order to improve the vehicle's road handling. Load sensing technology is also used in, e.g., payload weight measurements on machines such as trucks for bulk transport, warehouse trolleys, household washing machines, conveyor belts, elevators, cranes and hoisting equipment, etc.
Load sensing technology is also used in condition monitoring of machines such as, e.g., wind turbines, industrial equipment, marine propulsion systems, aeronautic propulsion systems, etc.
A specific branch of load sensing technology relates to the sensing of a load on a rolling element bearing. Load sensing enables to determine the running conditions of the rolling element bearing, e.g., for calculating the service life, monitoring over-load conditions and under-load conditions, etc.
The load on the rolling element bearing causes an elastic deformation of the rolling element bearing. Typical methods, known in the art, of measuring the load on a rolling element bearing include sensing the local deformations of the housing of the rolling element bearing, or sensing the local deformations of the rolling element bearing, caused by the load on the rolling element bearing. Consider, for example, a typical rolling element bearing designed to support a radial load or a typical rolling element bearing designed to support a predominantly radial load and in addition some axial loads. Such a rolling element bearing comprises a concentric arrangement of an inner ring, an outer ring and a plurality of rolling elements accommodated between the inner ring and the outer ring. One or more strain gauges are positioned at a cylindrical outer surface of the outer ring. In operational use of the rolling element bearing, the strain gauges provide signals representative of the local deformations of the outer ring, from which the load can be determined For more background information, also see, e.g., U.S. Pat. No. 7,444,888, issued to Hendrik Anne Mol and Gerrit Cornelis van Nijen, and U.S. Pat. No. 7,389,701, issued to Hendrik Anne Mol, both incorporated herein by reference.